使用委托解决不同系统加载程序问题

使用委托解决不同系统加载程序问题

需求

彩虹狗需要增加64位驱动，解决方法可以不修改程序，在做安装程序的时候使用不同的版本，只需要文件名相同就可以。

而我之前看了些有关委托方法的使用，就想尝试一下在不调整其它配置的情况下，支持不同环境的调用。

分析

原先的代码中，对外提供的公开方法是直接调用32位DLL中的函数，如下

Friend Class Dog …… Declare Function Check_Dog Lib "htbdog.dll" Alias "Check_Dog" (ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByRef RetCode As Integer) As Integer Declare Function Read_Dog Lib "htbdog.dll" Alias "Read_Dog" (ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByVal DogAddr As Integer, ByVal DogBytes As Integer, ByVal DogData() As Byte, ByRef RetCode As Integer) As Integer Declare Function Write_Dog Lib "htbdog.dll" Alias "Write_Dog" (ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByVal DogAddr As Integer, ByVal DogBytes As Integer, ByVal DogData() As Byte, ByRef RetCode As Integer) As Integer …… End Class

而新增64位DLL中的函数，其名称、形参、返回值是与32位DLL完全相同的，只是文件名不同（32位为htbdog.dll，64位为htbdog64.dll）

本想使用反射的方法进行动态调用，但是考虑到反射调用的性能比较差，所以尝试使用委托方法来实现

解决思路如下：

1. 为32位与64位的DLL分别声明调用函数，函数名称以32、64结尾来区别，例如：

Declare Function Check_Dog32 Lib "htbdog.dll" Alias "Check_Dog" (ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByRef RetCode As Integer) As Integer Declare Function Check_Dog64 Lib "htbdog64.dll" Alias "Check_Dog" (ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByRef RetCode As Integer) As Integer

2. 声明委托方法，形参与各个DLL中函数一致

Private Delegate Function gateCheck_Dog(ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByRef RetCode As Integer) As Integer Private entCheck_Dog As gateCheck_Dog

3. 在实例化Dog对象时，根据当前系统的不同，实例化具体委托对象的方法。例如

Public Sub New() 'IntPtr.Size = 4 32 位系统，使用htbdog.dll If IntPtr.Size = 4 Then entCheck_Dog = New dCheck_Dog(AddressOf Check_Dog32) 　…… Else entCheck_Dog = New dCheck_Dog(AddressOf Check_Dog64) 　…… End If End Sub

4. 对外公开方法调用委托对象实现

Public Function Check_Dog(ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByRef RetCode As Integer) As Integer Return entCheck_Dog.Invoke(DogCascade, DogPassword, RetCode) End Function

这样调整之后，对外部公开的方法调用没有发生变化，而只是在内部进行了处理，相比反射的动态调用性能好一些

示例代码

Friend Class Dog …… '来自32位DLL的函数声明 #Region "硬件狗操作函数（32位系统）" Declare Function Check_Dog32 Lib "htbdog.dll" Alias "Check_Dog" (ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByRef RetCode As Integer) As Integer Declare Function Read_Dog32 Lib "htbdog.dll" Alias "Read_Dog" (ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByVal DogAddr As Integer, ByVal DogBytes As Integer, ByVal DogData() As Byte, ByRef RetCode As Integer) As Integer Declare Function Write_Dog32 Lib "htbdog.dll" Alias "Write_Dog" (ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByVal DogAddr As Integer, ByVal DogBytes As Integer, ByVal DogData() As Byte, ByRef RetCode As Integer) As Integer …… #End Region '来自64位DLL的函数声明 #Region "硬件狗操作函数（64位系统）" Declare Function Check_Dog64 Lib "htbdog64.dll" Alias "Check_Dog" (ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByRef RetCode As Integer) As Integer Declare Function Read_Dog64 Lib "htbdog64.dll" Alias "Read_Dog" (ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByVal DogAddr As Integer, ByVal DogBytes As Integer, ByVal DogData() As Byte, ByRef RetCode As Integer) As Integer Declare Function Write_Dog64 Lib "htbdog64.dll" Alias "Write_Dog" (ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByVal DogAddr As Integer, ByVal DogBytes As Integer, ByVal DogData() As Byte, ByRef RetCode As Integer) As Integer …… #End Region '委托函数声明与DLL函数的参数、返回类型一致 Private Delegate Function gateCheck_Dog(ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByRef RetCode As Integer) As Integer Private Delegate Function gateRead_Dog(ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByVal DogAddr As Integer, ByVal DogBytes As Integer, ByVal DogData() As Byte, ByRef RetCode As Integer) As Integer Private Delegate Function gateWrite_Dog(ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByVal DogAddr As Integer, ByVal DogBytes As Integer, ByVal DogData() As Byte, ByRef RetCode As Integer) As Integer …… '声明委托对象为指定的委托函数 Private entCheck_Dog As gateCheck_Dog Private entRead_Dog As gateRead_Dog Private entWrite_Dog As gateWrite_Dog …… '实例化时，根据当前系统的不同，实例化委托对象的对应函数 Public Sub New() 'IntPtr.Size = 4 32 位系统，使用htbdog.dll If IntPtr.Size = 4 Then entCheck_Dog = New dCheck_Dog(AddressOf Check_Dog32) entRead_Dog = New dRead_Dog(AddressOf Read_Dog32) entWrite_Dog = New dWrite_Dog(AddressOf Write_Dog32) 　…… Else entCheck_Dog = New dCheck_Dog(AddressOf Check_Dog64) entRead_Dog = New dRead_Dog(AddressOf Read_Dog64) entWrite_Dog = New dWrite_Dog(AddressOf Write_Dog64) 　…… End If End Sub '公开函数调用通过委托对象进行调用 Public Function Check_Dog(ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByRef RetCode As Integer) As Integer Return entCheck_Dog.Invoke(DogCascade, DogPassword, RetCode) End Function Public Function Read_Dog(ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByVal DogAddr As Integer, ByVal DogBytes As Integer, ByVal DogData() As Byte, ByRef RetCode As Integer) As Integer Return entRead_Dog(DogCascade, DogPassword, DogAddr, DogBytes, DogData, RetCode) End Function Public Function Write_Dog(ByVal DogCascade As Integer, ByVal DogPassword As Integer, ByVal DogAddr As Integer, ByVal DogBytes As Integer, ByVal DogData() As Byte, ByRef RetCode As Integer) As Integer Return entWrite_Dog(DogCascade, DogPassword, DogAddr, DogBytes, DogData, RetCode) End Function End Class